This invention relates to devices for detecting underground utility lines or elements, and in particular, to devices which are buried with underground lines or elements for providing an early detection or warning of such utility lines or elements during excavation.
There are many different types of underground utility lines or elements, such as wires, cables, conduit, sewer pipes and sewer connections, valves, water lines, gas lines, and other like lines or elements. These lines or elements are typically used for electrical power or signal transmission, as well as for conveying solids, liquids and gases. When such utility lines or elements are excavated, their exact location must be identified in order to prevent damage thereto during excavation.
Underground utility lines or elements are usually located by sending appropriate personnel out to the excavation site to flag or otherwise mark the ground overlying the utility lines or elements. In order to accomplish this, the personnel must rely on certain methods and techniques for identifying the location of the utility. For example, buried power or water lines are often designated as being located a given number of feet below the surface of the ground or from some reference or bench mark.
Unfortunately, frequently referenced marks may disappear and various construction projects may alter the ground level. Consequently, when excavation becomes necessary for making repairs, upgrades, or alterations, the precise location of the utility lines or elements is virtually incapable of being determined. This makes their excavation a generally inexact undertaking as the location of the utility line or element must be estimated. Hence, cautious excavation either manually or with power equipment must be undertaken. Frequently, an erroneous estimate can result in damage to the excavated utility line or element, or other utility lines or elements may be damaged which were not expected to be at the location. Further, indiscriminate or careless excavation, particularly with power equipment and often with manually operated power equipment can be hazardous to personnel engaged in such operations. This is particularly true when the underground utility carries a toxic chemical material or is an electric or gas supply line.
The prior art has made many attempts to address this problem. For example, certain electronic techniques and methods have been developed which assist in the location of underground utility lines or elements during excavation. However, these techniques are often not used by construction crews for various reasons.
Another technique and method for locating underground utility lines or elements uses generally inexpensive frangible and non-frangible tapes with warning indicia or other attention-compelling means. These tapes are usually buried above the utility line or element so that they rest directly on top of or slightly above the utility line or element.
The problem with these tapes is that once the tape is found by the excavation equipment, the equipment more often than not, has already damaged the utility line or element. Additionally, injury to the excavation personnel as a result of the damage to the utility line or element may have also occurred.
Accordingly, a device is needed for providing early detection or warning of underground utility lines or elements during excavation.
In accordance with the invention, a device for ground burial with an underground utility line or element and useful for providing early detection of the utility line or element during excavation. The device comprises at least one sheet of non-conductive material, indicia on the sheet forming a cautionary message that indicates the presence of an underground utility line or element, and at least one support element coupled to the sheet for vertically positioning the device in the ground.
In further accordance with the invention, a method for providing early detection of an underground utility line or element during the excavation. The method comprises the steps of providing at least one of the devices described immediately above and burying it in the ground along a side of an underground utility line or element so that the device is positioned vertically in the ground and extends up toward the surface of the ground from the underground level of the utility line or element.